In some downhole operations, for example, hydraulic fracturing (“fracking”) operations, a tool is actuated downhole. A downhole tool arrangement sometimes includes a tubular surrounding a sliding member. The sliding member is initially stationary, but can be actuated downhole so that it can slide axially relative to the tubular. Pressure can then be applied to the sliding member to slide the member relative to the tubular. The relative movement between the sliding member and tubular can open a port, for example, to allow a fracking operation.
It should be understood that the various embodiments are not limited to the arrangements and instrumentality shown in the drawings.